关于社会群体线索对行为预测的影响及其认知机制，不同于先前研究以行为这一单维视角为主，本项目拟从行为的行动目标和动作形式（如何实现目标）两个特征维度出发对该问题进行探讨。基于行为合理性原则（以最经济的动作形式实现行动目的）以及群体规范表征的分析，本项目提出：（1）当动作形式与行动目标符合合理性原则时，人们根据对群体的描述性规范表征，预测他人会执行与内群体成员具有相同行动目标的行为；（2）反之，人们基于对群体强制性规范的表征，预测他人会执行与内群体成员具有相同动作形式的行为。为检验该假设，本项目拟采用行为研究、脑电与经颅直流电刺激（tDCS）技术相结合的方法，系统操纵社会群体线索的存在性，以及动作形式与行动目标间的合理性关系，在现象层面探明社会群体线索对行为预测的影响，并揭示该现象是由于对群体的描述性规范还是强制性规范表征所致。在此基础上构建理论，阐明社会群体线索如何影响行为预测的认知机制。

Previous research has invested much effort on whether and how the action prediction is influenced by the social group cues, treating the action as a unidimensional construct. However, it is suggested that the action should be constructed as two dimensions with action goal (i.e., the directed goal) and action means (i.e., how to approach the goal). The current project takes the perspective of this two-dimensional construct to investigate whether and how the social group cue affects the action prediction. On the basis of elaborating the properties that the individuals follow the principle of rationality to implement actions (i.e., adopting the most efficient action means to realize the goal) and their actions are constrained by social norms in a group, this project proposes a hypothesis about that: (1) When the relation between action means and action goal falls into the principle of rationality, people predict that the expected individual should implement the action with the same directed goal as the members of its belonging social group, due to the descriptive norm of this group; (2) Otherwise, the expected individual should be predicted to implement the action with the same action means as the members of its belonging social group, for its prescriptive norm of group. To test this hypothesis, we are planning to use behavioral, EEG/ERP and tDCS methods. Through manipulating the properties of social group cues and the relation between action means and action goal, this project is aimed to first investigate what patterns should be exhibited about the influence of social group cues on action prediction, and then explore whether such patterns are driven by the expectation from descriptive norm or prescriptive norm of a social group. Further, based on experimental findings, we expect to construct a preliminary theory about the cognitive mechanisms how the action prediction is influenced by the social group cues, from the perspective of the two-dimensional construct for action.